Search results
Results from the WOW.Com Content Network
However, in most fielded systems, unwanted clutter and interference sources mean that the noise level changes both spatially and temporally. In this case, a changing threshold can be used, where the threshold level is raised and lowered to maintain a constant probability of false alarm. This is known as constant false alarm rate (CFAR) detection.
Since V is a random variable and is a constant (), the false positive ratio is also a random variable, ranging between 0–1. The false positive rate (or "false alarm rate") usually refers to the expectancy of the false positive ratio, expressed by (/).
Constant False Alarm Rate, a form of Automatic Gain Control (AGC), is a method that relies on clutter returns far outnumbering echoes from targets of interest. The receiver's gain is automatically adjusted to maintain a constant level of overall visible clutter.
Constant false alarm rate processing is used to examine each FFT output to detect signals. This is an adaptive process that adjusts automatically to background noise and environmental influences. There is a cell under test, where the surrounding cells are added together, multiplied by a constant, and used to establish a threshold.
Detection using constant false alarm rate (CFAR) scheme; Association and tracking of object returns in range/Doppler space, known as "line tracking" Association and fusion of line tracks from each transmitter to form the final estimate of an object's location, heading and speed. These are described in greater detail in the sections below.
The normal deviate mapping (or normal quantile function, or inverse normal cumulative distribution) is given by the probit function, so that the horizontal axis is x = probit(P fa) and the vertical is y = probit(P fr), where P fa and P fr are the false-accept and false-reject rates.
CFAR may refer to: Centre for Freudian Analysis and Research; Collaborative Forecasting and Replenishment; CFAR (AM), a radio station (590 AM) licensed to Flin Flon, Manitoba, Canada; Constant false alarm rate; Center for Applied Rationality
Uses pulse compression, MTI (Moving Target Indicator) and CFAR (Constant False Alarm Rate) Traveling Wave Tube (TWT) amplifier; Independent search capability in 10 " X 10 " Able to track both surface and airborne targets; TV tracking/Laser Range finding